original customer report:
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We are exploring to replace the *old* javapackager with the upcoming
jpackage tool and encounter an issue on Windows.

The javapackager tool allowed to create exe installers (by means of
InnoSetup) and msi installers using WiX toolkit. With jpackage the
InnoSetup exe installers were abandoned and instead WiX is used to create
msi and exe installers.

Until now we are shipping InnoSetup exe installers and tried to update now
with jpackage to msi installers. At first msi installation seems to work
fine (no error dialogs or so). When running the application it simply does
not start (Windows also shows it twice in the list of installed
applications).

The only *working* solution we found was to *manually* uninstall the old
application before starting msi installer.
Any future update with msi installers work fine. But the first update fails!

Since this seems a very common use-case I wonder whether there is a known
solution to this problem. Is this a known issue? Are there any practices
one can follow so that costumers do not need to manually uninstall the
existing application first.
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later customer reported:
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I believe the
necessary change to let upgrades succeed is rather minimal.

The WIX template jpackage uses

<Product Id="*" Name="$(var.AppName)" Language="1033"
Version="$(var.AppVersion)" Manufacturer="$(var.AppVendor)"
UpgradeCode="$(var.AppUpgradeCode)">

needs to have

<Upgrade Id="$(var.AppUpgradeCode)" />

as well within the product element.
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